检索结果-内蒙古大学图书馆

OCEANS

作者： T. Nicosevici R. Garcia M. Carreras M. Villanueva Computer Vision and Robotics Group Institute of Informatics and Applicaitons University of Gironn E.P.S. Girona Spain

This work provides a general description of the multi sensor data fusion concept, along with a new classification of currently used sensor fusion techniques for unmanned underwater vehicles (UUV). Unlike previous proposals that focus the classification on the sensors involved in the fusion, we propose a synthetic approach that is focused on the techniques involved in the fusion and their applications in UUV navigation. We believe that our approach is better oriented towards the development of sensor fusion systems, since a sensor fusion architecture should be first of all focused on its goals and then on the fused sensors.

关键词： Sensor fusion Underwater vehicles Navigation Robot sensing systems Acoustic sensors Sensor systems Intelligent sensors Mobile robots Oceans Global Positioning System

来源：评论

学校读者我要写书评

暂无评论

Feature based slam using side-scan salient objects

Feature based slam using side-scan salient objects

引用

OCEANS

作者： Josep Aulinas Xavier Lladó Joaquim Salvi Yvan R. Petillot Computer Vision and Robotics Group Institute of Informatics and Applications University of Girona Girona Spain Oceans Systems Laboratory School of Engineering and Physical Sciences Heriot-Watt University Edinburgh UK

Different underwater vehicles have been developed in order to explore underwater regions, specially those of difficult access for humans. Autonomous Underwater Vehicles (AUVs) are equipped with on-board sensors, which provide valuable information about the vehicle state and the environment. This information is used to build an approximate map of the area and estimate the position of the vehicle within this map. This is the so called Simultaneous Localization and Mapping (SLAM) problem. In this paper we propose a feature based submapping SLAM approach which uses side-scan salient objects as landmarks for the map building process. The detection of salient features in this environment is a complex task, since sonar images are noisy. We present in this paper an algorithm based on a set of image preprocessing steps and the use of a boosted cascade of Haar-like features to perform the automatic detection in side-scan images. Our experimental results show that the method produces consistent maps, while the vehicle is precisely localized.

关键词： Simultaneous localization and mapping Vehicles Feature extraction Sonar detection Object detection Sonar navigation

来源：评论

学校读者我要写书评

暂无评论

Feature extraction for underwater visual SLAM

Feature extraction for underwater visual SLAM

引用

OCEANS - Europe

作者： Josep Aulinas Marc Carreras Xavier Llado Joaquim Salvi Rafael Garcia Ricard Prados Yvan R. Petillot Computer Vision and Robotics Group Institute of Informatics and Applications University of Girona Girona Spain Oceans Systems Laboratory School of Engineering and Physical Sciences Heriot-Watt University Edinburgh UK

Detecting and selecting proper landmarks is a key issue to solve Simultaneous Localization and Mapping (SLAM). In this work, we present a novel approach to perform this landmark detection. Our approach is based on using three sources of information: 1) three-dimensional topological information from SLAM; 2) context information to characterize regions of interest (RoI); and 3) features extracted from these RoIs. Topological information is taken from the SLAM algorithm, i.e. the three-dimensional approximate position of the landmark with a certain level of uncertainty. Contextual information is obtained by segmenting the image into background and RoIs. Features extracted from points of interest are then computed by using common feature extractors such as SIFT and SURF. This information is used to associate new observations with known landmarks obtained from previous observations. The proposed approach is tested under a real unstructured underwater environment using the SPARUS AUV. Results demonstrate the validity of our approach, improving map consistency.

关键词： Feature extraction Simultaneous localization and mapping Cameras Robustness Vehicles Uncertainty Optical imaging

来源：评论

学校读者我要写书评

暂无评论

O 2 CA 2 : A New Hybrid Control Architecture for a Low Cost AUV

引用

IFAC Proceedings Volumes 2001年第7期34卷 311-316页

作者： P. Ridao M. Carreras J. Batlle J. Amat Computer Vision and Robotics Group Institute of Informatics and Applications University of Girona Edifici Politècnica II Campus Montilivi 17071 Girona Spain Department of Automatic Control and Computer Engineering Politechnical University of Catalunya. Pau Gargallo n°5 08028 Barcelona (Spain).

The Object Oriented Control Architecture for Autonomy (O 2 CA 2 ) is a control architecture being developed at the University of Girona for the GARBI underwater vehicle. Conceived as a hybrid, it is organised in three layers (Deliberative, Control Execution and Reactive) merging the deliberation mechanisms of planning with reactive behaviours in charge of controlling the robot. The aim of this paper is to provide an overall description of the whole architecture and an in depth description of the Reactive-layer. The concepts of the architecture have been tested with the simulation of a simple mission consisting of navigating through a sequence of way-points while avoiding contact with obstacles.

关键词： Autonomous Vehicles Control architectures behaviour fuzzy systems guidance navigation marine systems

来源：评论

学校读者我要写书评

暂无评论

Accuracy estimation of a new omnidirectional 3D vision sensor

Accuracy estimation of a new omnidirectional 3D vision senso...

引用

IEEE International Conference on Image Processing

作者： R. Orghidan J. Salvi E.M. Mouaddib Institute of Informatics and Applications Computer Vision and Robotics Group University of Girona Catalonia Spain Centre de Robotique Électrotechnique et Automatique Université de Picardie Jules-Verne Amiens France

We present a computer vision system that associates omnidirectional vision with structured light with the aim of obtaining depth information for a 360 degrees field of view. The approach proposed in this article combines an omnidirectional camera with a panoramic laser projector. The article shows how the sensor is modelled and its accuracy is proved by means of experimental results. The proposed sensor provides useful information for robot navigation applications, pipe inspection, 3D scene modelling etc.

关键词： Cameras Robot vision systems Robot sensing systems Layout Mirrors Application software computer vision Navigation robotics and automation Laser modes

来源：评论

学校读者我要写书评

暂无评论

Towards robust monocular visual odometry for flying robots on planetary missions

arXiv

引用

arXiv 2021年

作者： Wudenka, Martin Müller, Marcus G. Demmel, Nikolaus Wedler, Armin Triebel, Rudolph Cremers, Daniel Stürzl, Wolfgang Institute of Robotics and Mechatronics German Aerospace Center DLR Computer Vision Group Department of Informatics Technical University of Munich Germany Autonomous Systems Lab ETH Zurich Switzerland

In the future, extraterrestrial expeditions will not only be conducted by rovers but also by flying robots. The technical demonstration drone Ingenuity, that just landed on Mars, will mark the beginning of a new era of exploration unhindered by terrain traversability. Robust self-localization is crucial for that. Cameras that are lightweight, cheap and information-rich sensors are already used to estimate the ego-motion of vehicles. However, methods proven to work in man-made environments cannot simply be deployed on other planets. The highly repetitive textures present in the wastelands of Mars pose a huge challenge to descriptor matching based approaches. In this paper, we present an advanced robust monocular odometry algorithm that uses efficient optical flow tracking to obtain feature correspondences between images and a refined keyframe selection criterion. In contrast to most other approaches, our framework can also handle rotation-only motions that are particularly challenging for monocular odometry systems. Furthermore, we present a novel approach to estimate the current risk of scale drift based on a principal component analysis of the relative translation information matrix. This way we obtain an implicit measure of uncertainty. We evaluate the validity of our approach on all sequences of a challenging real-world dataset captured in a Mars-like environment and show that it outperforms state-of-the-art approaches. The source code is publicly available at: https://***/DLR-RM/granite. Copyright © 2021, The Authors. All rights reserved.

关键词： Principal component analysis

来源：评论

学校读者我要写书评

暂无评论

Steering and Depth Control of an Underwater Robot Using Fuzzy-Like PD Controller

引用

IFAC Proceedings Volumes 2000年第21期33卷 239-244页

作者： I.S. Akkizidis G.N. Roberts P. Ridao J. Batlle Mechatronics Research Centre University of Wales College Newport Allt-yr-yn Campus PO Box 180 Newport South Wales NP9 5XR UK Computer Vision and Robotics Group Institute of Informatics and Applications Edifici Politècnica II Campus Montilivi 7071-Girona SPAIN

The design of a steering and depth control of an underwater vehicle is of interest from the point of view of motion stabilisation as well as manoeuvring performance. The paper describes how a Fuzzy-like Proportional Derivative Controller (Fuzzy-like PD Control) is used to control the course-changing and course-keeping tracking mission and motion of an underwater vehicle. The idea for this type of control architecture is to identify the optimum values, in terms of control performance and robustness, of the parameters of the F-like PD Controller. These parameters may be the scaling factors that are applied in the input/output of the PD part of the controller as well as the fuzzy sets of the fuzzy part of the controller. The values of the scaling factors for the error, the change-of-error and the control output are optimised based on experiments. In this work a method has been developed to control the yaw and depth of an underwater robot in terms of course-changing and course-keeping. The controller is synthesised in two parts. Firstly it is applied in horizontal xy and secondly in vertical xz surface. Experiments in a real environment were planned using the Taguchi Design of Experiments and performed to investigate the capabilities of the controller. The results are presented and analysed extensively.

关键词： Fuzzy like-PD Controller Yaw and Depth Control Taguchi Design of Experiments

来源：评论

学校读者我要写书评

暂无评论

Partially calibrated semi-generalized pose from hybrid point correspondences

arXiv

引用

arXiv 2022年

作者： Bhayani, Snehal Larsson, Viktor Sattler, Torsten Heikkilä, Janne Kukelova, Zuzana Center for Machine Vision and Signal Analysis University of Oulu Finland Czech Institute of Informatics Robotics and Cybernetics Czech Technical University Prague Czech Republic Computer Vision and Geometry Group Department of Computer Science ETH Zürich Switzerland Visual Recognition Group Faculty of Electrical Engineering Czech Technical University Prague Czech Republic

In this paper we study the problem of estimating the semi-generalized pose of a partially calibrated camera, i.e., the pose of a perspective camera with unknown focal length w.r.t. a generalized camera, from a hybrid set of 2D-2D and 2D-3D point correspondences. We study all possible camera configurations within the generalized camera system. To derive practical solvers to previously unsolved challenging configurations, we test different parameterizations as well as different solving strategies based on state-of-the-art methods for generating efficient polynomial solvers. We evaluate the three most promising solvers, i.e., the H51f solver with five 2D-2D correspondences and one 2D-3D correspondence viewed by the same camera inside generalized camera, the H32f solver with three 2D-2D and two 2D-3D correspondences, and the H13f solver with one 2D-2D and three 2D-3D correspondences, on synthetic and real data. We show that in the presence of noise in the 3D points these solvers provide better estimates than the corresponding absolute pose solvers. Copyright © 2022, The Authors. All rights reserved.

关键词： Cameras

来源：评论

学校读者我要写书评

暂无评论

P1AC: Revisiting Absolute Pose From a Single Affine Correspondence

P1AC: Revisiting Absolute Pose From a Single Affine Correspo...

引用

International Conference on computer vision (ICCV)

作者： Jonathan Ventura Zuzana Kukelova Torsten Sattler Dániel Baráth Department of Computer Science & Software Engineering Cal Poly San Luis Obispo Visual Recognition Group Faculty of Electrical Engineering Czech Technical University in Prague Czech Institute of Informatics Robotics and Cybernetics Czech Technical University in Prague Computer Vision and Geometry Group ETH Zürich

Affine correspondences have traditionally been used to improve feature matching over wide baselines. While recent work has successfully used affine correspondences to solve various relative camera pose estimation problems, less attention has been given to their use in absolute pose estimation. We introduce the first general solution to the problem of estimating the pose of a calibrated camera given a single observation of an oriented point and an affine correspondence. The advantage of our approach (P1AC) is that it requires only a single correspondence, in comparison to the traditional point-based approach (P3P), significantly reducing the combinatorics in robust estimation. P1AC provides a general solution that removes restrictive assumptions made in prior work and is applicable to large-scale image-based localization. We propose a minimal solution to the P1AC problem and evaluate our novel solver on synthetic data, showing its numerical stability and performance under various types of noise. On standard image-based localization benchmarks we show that P1AC achieves more accurate results than the widely used P3P algorithm. Code for our method is available at https://***/jonathanventura/P1AC/.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Absolute Pose from One or Two Scaled and Oriented Features

Absolute Pose from One or Two Scaled and Oriented Features

引用

Conference on computer vision and Pattern Recognition (CVPR)

作者： Jonathan Ventura Zuzana Kukelova Torsten Sattler Dániel Baráth Department of Computer Science & Software Engineering Cal Poly San Luis Obispo Faculty of Electrical Engineering Visual Recognition Group Czech Technical University in Prague Czech Institute of Informatics Robotics and Cybernetics Czech Technical University in Prague Department of Computer Science Computer Vision and Geometry Group ETH Zürich

ISBN: (数字)9798350353006

ISBN: (纸本)9798350353013

Keypoints used for image matching often include an estimate of the feature scale and orientation. While recent work has demonstrated the advantages of using feature scales and orientations for relative pose estimation, relatively little work has considered their use for absolute pose estimation. We introduce minimal solutions for absolute pose from two oriented feature correspondences in the general case, or one scaled and oriented correspondence given a known vertical direction. Nowadays, assuming a known direction is not particularly restrictive as modern consumer devices, such as smartphones or drones, are equipped with Inertial Measurement Units (IMU) that provide the gravity direction by default. Compared to traditional absolute pose methods requiring three point correspondences, our solvers need a smaller minimal sample, reducing the cost and complexity of robust estimation. Evaluations on large-scale and public real datasets demonstrate the advantage of our methods for fast and accurate localization in challenging conditions. Code is available at https://***/danini/absolute-pose-from-oriented-and-sealed-features.

关键词： Location awareness Accuracy Simultaneous localization and mapping Measurement units Pose estimation Noise Inertial navigation

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：